Assembly and Method to Repair Thermoplastic Composites

ABSTRACT

An assembly to repair a thermoplastic composite. The assembly includes a heating device positioned on opposing sides of the thermoplastic composite. The heating device includes one or more susceptor with a Curie temperature to heat the thermoplastic composite. A pressure device applies a compressive force to the heating device. A pressure distribution device is positioned between the heating device and the thermoplastic composite. The pressure distribution device distributes the compressive force from the pressure device over areas of the opposing sides of thermoplastic composite.

TECHNOLOGICAL FIELD

The present disclosure relates generally to the field of thermoplasticcomposites and, more specifically, to the field of using susceptors withCurie temperatures to heat and repair thermoplastic composites.

BACKGROUND

Thermoplastic composites are used in a wide variety of contexts due totheir strength and relative light weight. Examples include but are notlimited to a variety of consumer products, building structures, and air,land, and water-based vehicles. One drawback to thermoplastic compositesis the occurrence of delamination of the plies. One instance ofdelamination occurs when a hole is drilled or otherwise formed in thethermoplastic composite. Damaged thermoplastic structures have beendifficult to repair.

Scarf-type repairs are one current method of repairing delaminatedthermoplastic composites. Scarf repairs include removing the section ofdelaminated thermoplastic composite and replacing it with new material.To reduce the strains at the repair location, the new material isblended out to create a “scarf” joint. Scarf joints are typically doneat a 30:1 taper ratio (i.e., for every unit of depth, the repair site istapered out 30 units of width). This results in the removal of a largeamount of undamaged thermoplastic composite that is in proximity to therepair location. For example, a one inch diameter delaminationsurrounding a fastener hole location in a 20-ply thick laminate wouldrequire removal of about a ten inch diameter around the fastener hole.

Scarf repairs also require an interfacial adhesive between the newmaterial and the exposed thermoplastic material at the repair location.Using film adhesives with thermoplastic laminates requires specialsurface preparation methods to insure a strong bond. This includes anatmospheric plasma surface treatment that is difficult at least becausethe plasma processing parameters (standoff distance, rate of travel,overlap, impingement angle, etc.) are difficult to replicate withoutusing robotics.

Scarf repairs also require a relatively high heat to consolidate thethermoplastic. Traditional heat blankets may not be capable of reachingthe desired temperature. Further, managing the temperature delta acrossthe repair area is challenging when using traditional heat blankets andcan result in either under-heating or over-heating the new materialswhich would result in an unacceptable repair.

SUMMARY

One aspect is directed to an assembly to repair a thermoplasticcomposite. The assembly comprises a heating device comprising first andsecond heating elements positioned on opposing sides of thethermoplastic composite. The first heating element comprises a firstsusceptor in contact with a first conductor and the second heatingelement comprises a second susceptor in contact with a second conductor.The first and second susceptors each comprises a Curie temperature toheat and reconsolidate the thermoplastic composite. A pressure deviceapplies a compressive force to the heating device. A pressuredistribution device is positioned between the heating device and thethermoplastic composite. The pressure distribution device has a greaterwidth measured along the thermoplastic composite than the heating deviceto distribute the compressive force from the pressure device over areasof the opposing sides of thermoplastic composite.

In another aspect, the pressure distribution device comprises a firstmember positioned between the first heating element and a first side ofthe thermoplastic composite and a second member positioned between thesecond susceptor and a second side of the thermoplastic composite with awidth of each of the first and second members being greater than theheating device.

In another aspect, the first and second members comprise a tapered outeredge.

In another aspect, the pressure distribution device directly contactsagainst the heating device on each side of the thermoplastic composite.

In another aspect, the pressure device comprises a rod sized to extendthrough the thermoplastic composite with the first heating element andthe first susceptor attached to the rod on a first side of thethermoplastic composite and the second heating element and the secondsusceptor attached to the rod on a second side of the thermoplasticcomposite.

In another aspect, the rod is constructed from a susceptor alloy and hasa Curie temperature to heat the thermoplastic composite when the rod isheated by the heating device.

In another aspect, the Curie temperature of the first susceptor isdifferent than the second susceptor.

In another aspect, washer stacks are positioned along the rod that applya force to the first and second heating elements to maintain thecompressive force.

One aspect is directed to an assembly to repair a thermoplasticcomposite. The assembly comprises a threaded rod and a nut threaded tothe threaded rod on a first side of the thermoplastic composite and anattachment on the threaded rod on a second side of the thermoplasticcomposite. First and second members are positioned on the threaded rodwith the first member positioned between the nut and the first side ofthe thermoplastic composite and the second member is positioned betweenthe attachment and the second side of the thermoplastic composite. Firstand second heating elements are positioned on the threaded rod with thefirst heating element positioned between the nut and the first memberand the second heating element positioned between the attachment and thesecond member with the first heating element comprising a firstsusceptor and a first conductor and the second heating elementcomprising a second susceptor and a second conductor. The first andsecond susceptors each comprise a Curie temperature to heat andreconsolidate the thermoplastic composite.

In another aspect, the first and second members comprise an inner sidethat contacts against the thermoplastic composite and an outer side thatcontacts the first and second heating elements respectively.

In another aspect, the first and second members comprise a width that isgreater than the first and second heating elements.

In another aspect, the first susceptor contacts against the firstconductor and the second susceptor contacts against the secondconductor.

In another aspect, the nut is a first nut, and the attachment is asecond nut that is threaded to the threaded rod.

In another aspect, the first heating element directly contacts againstthe first member and the second heating element directly contactsagainst the second member.

In another aspect, the threaded rod is constructed from a susceptoralloy that heats and reconsolidates the thermoplastic composite whenheated by one or both the first and second heating elements.

One aspect is directed to a method of repairing a thermoplasticcomposite. The method comprises: compressing a delaminated section ofthe thermoplastic composite between a first member at the first side ofthe thermoplastic composite and a second member at a second side of thethermoplastic composite; inductively heating a first heating elementthat is positioned against the first member and a second heating elementthat is positioned against the second member with each of the first andsecond heating elements comprising a susceptor and a conductor in astacked configuration and with each of the susceptors comprising aCurrie temperature; transferring heat from the first heating element tothe first member and from the second heating element to the secondmember; and heating the thermoplastic composite through the first andsecond members and reconsolidating the delaminated section.

In another aspect, the method comprises: positioning a threaded rodthrough an opening in the thermoplastic composite; applying a torque toa nut on the threaded rod; and applying a compressive force to the firstand second heating elements and the first and second members.

In another aspect, the method comprises inductively heating the threadedrod to a corresponding Currie temperature and heating the thermoplasticcomposite with the threaded rod.

In another aspect, the method includes positioning the first and secondmembers outward beyond the first and second heating elementsrespectively and creating a thermal transition zone along sections ofthe first and second members that extend outward beyond the first andsecond heating elements.

In another aspect, the method comprises positioning a first one of thesusceptors directly against the first member and a second one of thesusceptors directly against the second member.

The features, functions and advantages that have been discussed can beachieved independently in various aspects or may be combined in yetother aspects, further details of which can be seen with reference tothe following description and the drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side schematic view of an assembly that includes a pressuredevice, a pressure distribution device, and a heating device.

FIG. 2 is a side view of an assembly mounted to a thermoplasticcomposite.

FIG. 3 illustrates a side view a hole in the thermoplastic compositethat is delaminated.

FIG. 4 is a side view of an assembly positioned in the hole of FIG. 3.

FIG. 5 is a side view of the assembly of FIG. 4 in a tightenedconfiguration.

FIG. 6 is a side schematic view of the assembly of FIG. 5 with inductioncoils and a controller.

FIG. 7 is a schematic diagram of a controller operatively connected to apower supply and induction coils.

FIG. 8 is a flowchart diagram of a method of repairing a thermoplasticcomposite.

DETAILED DESCRIPTION

FIG. 1 illustrates a schematic view of an assembly 10 to repair athermoplastic composite 100. The assembly 10 includes a heating device40 that is positioned on opposing sides of the thermoplastic composite100. The heating device 40 includes one or more susceptors with a Curietemperature to heat the thermoplastic composite 100. A pressure device20 applies a compressive force to the heating device 40. A pressuredistribution device 30 is positioned between the heating device 40 andthe thermoplastic composite 100. The pressure distribution device 30distributes the compressive force from the pressure device 20 over areasof the opposing first and second sides 101, 102 of thermoplasticcomposite 100.

The pressure device 20 is configured to apply a compressive force fromopposing sides of the thermoplastic composite 100. As illustrated inFIG. 2, the pressure device 20 includes a rod 21 with a length to extendthrough the thermoplastic composite 100. The rod 21 includes a first end27 positioned on the first side 101 of the thermoplastic composite 100and a second end 28 positioned on the second side 102 of thethermoplastic composite 100. The rod 21 includes a centerline C/L. Inone example, the rod 21 is threaded along the entire length between thefirst and second ends 27, 28. Other examples can include threads alongone or more discrete sections of the length.

Attachments 22, 23 are connected to the rod 21. In one example, each ofthe attachments 22, 23 is a nut that is threaded onto the rod 21. Thenuts can be rotated to apply the desired compressive force to thethermoplastic composite 100. In another example, one of the attachments22, 23 is fixedly attached to the rod 21 and the other attachment 22, 23is movably attached to the rod 21. A fixed attachment can include but isnot limited to a head of the rod 21, or a washer or nut that is solderedor otherwise secured to the rod 21. In these examples, the pressure isapplied by rotating and moving the movable nut along the rod 21 with thefixed attachment remaining stationary.

The pressure distribution device 30 comprises members 31, 32 that arepositioned on opposing sides of the thermoplastic composite 100. Themembers 31, 32 each include an opening 37, 38 respectively that receivesthe rod 21. Each of the members 31, 32 includes a width W measuredperpendicular to the centerline C/L of the rod 21. The width W isgreater than a width of the heating device 40, and can be greater than awidth of the attachments 22, 23. As illustrated in FIG. 2, the members31, 32 can each include the same width W. Other examples include themembers 31, 32 having different widths that are each greater than theheating device 40. One or both of the members 31, 32 can be coated witha release agent to allow for their removal after consolidation of thethermoplastic composite 100.

The first member 31 includes an inner side 33 that faces towards thethermoplastic composite 100 and an opposing outer side 35 that facesaway from thermoplastic composite 100. Likewise, the second member 32includes an inner side 34 and an outer side 36. The inner sides 33, 34can be flat to facilitate contact with the thermoplastic composite 100.One or both of the members 31, 32 can have tapered outer edges. Thetapered outer edges reduce the point load at the edge of the members 31,32 once the pressure is applied. This reduces the possibility of themembers 31, 32 becoming depressed into the thermoplastic composite 100and causing a visible mark.

The large width of the first and second members 31, 32 distributes thepressure applied by the pressure device 20 over the repair area. Thelarge size also creates a thermal transition zone beyond the outer edgesof the heating device 40. The temperature at the outer sections of themembers 31, 32 that extend radially outward beyond the heating device 40are less than the temperature of the heating device 40. This thermalgradient prevents marking the thermoplastic composite 100 by the firstand second members 31, 32.

The pressure device 20 and pressure distribution device 30 can beconstructed from non-ferrous alloys of low electrical conductivity. Thisconstruction minimizes unintended heating that could be caused by eddycurrent. In one example, the pressure device 20 and pressuredistribution device 30 are constructed from titanium.

The heating device 40 heats the thermoplastic composite 100 above theconsolidation temperature. The heating device 40 includes a firstheating element 48 positioned on a first side of the thermoplasticcomposite 100, and a second heating element 49 positioned on a secondside of the thermoplastic composite 100. The first and second heatingelements 48, 49 include openings 46, 47 respectively that receive therod 21.

The first heating element 48 includes a susceptor 41 and a conductor 43that are stacked together. Likewise, the second heating element 49includes a stacked susceptor 42 and a conductor 44. FIG. 2 includes thesusceptors 41, 42 positioned towards the thermoplastic composite 100 andthe conductors 43, 44 positioned away from the thermoplastic composite100. The susceptors 41, 42 and conductors 43, 44 can also be stacked inan opposing orientation with the conductors 43, 44 in closer proximityto the thermoplastic composite 100 than the susceptors 41, 42. Eachheating element 48, 49 can include the same or different stackingarrangement.

The susceptors 41, 42 provide self-leveling temperature control and areconstructed from engineered ferrous alloys that have a Curie point thatcorresponds to the desired consolidation temperature of thethermoplastic composite 100. Examples include but are not limited toKovar and Molly Permalloy. The Curie point is the temperature at whichthe ferrous alloy loses its magnetic properties and loses its ability togenerate heat via magnetic hysteresis. Upon being heated to thistemperature, the susceptors 41, 42 will generate just enough heat tocompensate for thermal losses to the surrounding environment. In oneexample, the susceptors 41, 42 are constructed from engineered alloyswith the Curie point matching the desired consolidation temperature. Inanother example, the Curie point can be above the desired consolidationtemperature. In one example, the susceptors 41, 42 include a Curie pointthat is within 5° F. of the reconsolidation temperature of thethermoplastic composite 100. The susceptors 41, 42 can heat thethermoplastic composite 100 to various temperatures to provide forreconsolidation including but not limited to within a range of betweenabout 350° F.-825° F.

The width of the susceptors 41, 42 measured perpendicular to thecenterline C/L of the rod 21 can vary. In one example, the width isabout 1.0 to 1.5 inches larger than the repair area. In one specificexample with a hole having a 0.5 inch diameter and 0.25 inchdelaminations, the width of the susceptors 41, 42 is about 3-4 inches.

The conductors 43, 44 are sized and shaped to contact against thesusceptors 41, 4 2 respectively. Each of the conductors 43, 44 andsusceptors 41, 42 can include flat surfaces that contact when stackedtogether. In one example as illustrated in FIG. 2, the susceptors 41, 42include the same width as the conductors 43, 44. Other examples caninclude smaller or larger widths. The conductors 43, 44 can befabricated from a non-ferrous, highly conductive alloy. One specificexample includes copper. The high conductivity decreases the sensitivityof the susceptor 41, 42 to the orientation of the induction coil 110,111 (see FIG. 6).

Washer stacks 25 are positioned between the attachments 22, 23 and thefirst and second heating elements 48, 49. The washer stacks 25compensate for elongation of the rod 21 due to its coefficient ofthermal expansion and maintain the desired pressure on the thermoplasticcomposite 100. The washer stacks 25 can include various structures,including but not limited to Belleville washers and springs.

The thermoplastic composites 100 are formed from plies of unidirectionalfibers that are pre-impregnated with a thermoplastic matrix resin. Thefibers can be formed from a variety of materials, including but notlimited to aramids, polyolefins, metal, glass, carbon, boron, ceramic,mineral, and combinations. The thermoplastic matrix resin can be formedfrom a variety of substances, including but not limited to acrylics,fluorocarbons, polyamides (PA), polyethylenes (PE) such as polyethyleneterephthalate (PET), polyesters, polypropylenes (PP), polycarbonates(PC), polyurethanes (PU), polyetheretherketones (PEEK),polyetherketoneketones (PEKK), polyetherimides (PEI), and other materialcompositions. The fibers in the different plies can have variousorientations relative to one another to produce the desired strength.The plies can include a variety of thicknesses, with examples includingbut are not limited to thicknesses of between about 0.0025-0.0175inches.

FIGS. 3-6 illustrate the use of the assembly 10 to repair a delaminatedthermoplastic composite 100. As illustrated in FIG. 3, the thermoplasticcomposite 100 includes an opening 103 that extends between first andsecond sides 101, 102. The delamination can occur at an opening 103 thatis drilled or otherwise formed in the thermoplastic composite 100 afterfabrication. The plies 104 at the opening 103 are delaminated thusrequiring repair. In one example, no additional thermoplastic materialis removed during the repair process. In another example, one or moreportions of the delaminated material is removed and replaced in thescarf repair configuration providing the new material is within theeffective heating area.

FIG. 4 illustrates the assembly 10 positioned within the opening 103.The rod 21 extends through the opening 103 and the first heating element48 and first member 31 of the pressure distribution device 30 positionedat the first side 101. The second heating element 49 and second member32 are positioned at the second side 102. In the arrangement of FIG. 4,the attachments 22, 23 are positioned along the rod 21 such that nopressure is being applied to the thermoplastic composite 100.

Prior to attachment of the assembly 10, the proper one or more alloysare chosen for the susceptors 41, 42. The proper selection provides forheating the thermoplastic composite 100 to the desired temperature atthe desired power levels. Proper selection also avoids excessive heatingof the thermoplastic composite 100 irrespective of the input power. TheCurie temperature of the susceptors 41, 42 controls the absolutetemperature of the thermoplastic composite 100. The use of susceptoralloys provides for improved control of the heating process andtemperature uniformity in the thermoplastic composite 100 which resultsin more consistent repairs.

As illustrated in FIG. 5, one or both of the attachments 22, 23 aremoved along the rod 21 to apply the desired amount of pressure to thethermoplastic composite 100. The first member 31 is in direct contactwith the first side 101 of the thermoplastic composite 100 and thesecond member 32 is in direct contact with the second side 102 of thethermoplastic composite 100. In another example, a release film ordistribution layer is positioned on one or both of the first and secondsides 101, 102 such that one or both of the members 31, 32 do notdirectly contact against the thermoplastic composite 100.

The first heating element 48 is positioned in contact against the firstmember 31, and the second heating element 49 is positioned in contactagainst the second member 32. This can include the same or differentstacking orientations of the susceptors 41, 42 and conductors 43, 44 onthe first and second sides 101, 102 of the thermoplastic composite 100.

Once the desired pressure is applied to the thermoplastic composite 100,induction coils 110, 111 are placed over one or both exposed sections ofthe assembly 10. FIG. 6 illustrates induction coils 110, 111 placed overboth exposed sections of the assembly 10. A controller 120 is attachedto and controls the induction coils 110, 111.

As illustrated in FIG. 7, the controller 120 includes a processingcircuit 121 and a memory circuit 122. The processing circuit 121controls the operation of the induction coils 110, 111 and/or powersupply 130 according to program instructions stored in the memorycircuit 122. Within examples, the processing circuit 121 includes one ormore circuits, microcontrollers, microprocessors, hardware, or acombination thereof. Memory circuit 122 includes a non-transitorycomputer readable storage medium storing program instructions, such as acomputer program product, that configures the processing circuit 121 toimplement one or more of the techniques discussed herein. Memory circuit122 can include various memory devices such as, for example, read-onlymemory, and flash memory. In one example, memory circuit 122 is aseparate component as illustrated in FIG. 7. In another example, memorycircuit 122 is incorporated with the processing circuit 121.

The controller 120 is configured to send and/or receive signals to apower supply 130 to control the power supplied to the induction coils110, 111. Signals from the controller 120 can control the timing andsupply of power from the power supply 130 to the induction coils 110,111. FIG. 7 illustrates a single power supply 130 that provideselectricity to the induction coils 110, 111. Other examples can includetwo or more separate power supplies that provide power to the inductioncoils 110, 111.

An interface 123 provides for a user to enter commands to the processingcircuit 121 to control one or more aspects of the power supply 130and/or the induction coils 110, 111. The interface 123 can include oneor more displays for displaying information to the user and/or one ormore input devices such as but not limited to a keypad, touchpad, rollerball, and joystick.

During the repair, the induction coils 110, 111 are heated based onelectrical power supplied by the power supply 130. The induction coils110, 111 heat the susceptors 41, 42 to their engineered operatingtemperature. When a section on the susceptors 41, 42 reaches its Curietemperature, heat output in that section is rapidly diminished. Thesesections generate just enough heat to maintain the susceptors 41, 42engineered operating temperature. Other locations on the susceptors 41,42 that have not reached its Curie temperature are still able togenerate large amounts of heat until it also reaches its Curietemperature. This process provides for the application of uniformtemperatures across the repair area of the thermoplastic composite 100.

The susceptors 41, 42 are further not able to be overheated by theinduction coils 110, 111. Regardless of how much power is application,the use of Curie point control prevents overheating provided the correctsusceptor alloy is used for the susceptors 41, 42.

In one example, the components of the heating device 40 are constructedfrom a solid alloy. This construction provides for no wire elements thatcan short circuit or break.

The thermoplastic composite 100 has a predetermined operatingtemperature. Temperature ranges of repair processes include but are notlimited to a range of between about 350° F. to about 1950° F. In someexamples, the temperature is maintained relatively constant for severalminutes to several hours to complete the repair process. Other examplescan include a longer duration of relatively constant temperature.

After the repair time is complete, the induction coils 110, 111 areremoved. The pressure device 20 is loosened and removed from thethermoplastic composite 100. The heating device 40 and the pressuredistribution device 30 are likewise removed thus leaving the repairedthermoplastic composite 100.

FIG. 8 illustrates a method of repairing a thermoplastic composite 100.The method includes compressing a delaminated section of thethermoplastic composite 100 (block 200). This includes compressing thethermoplastic composite between a first member 31 at the first side 101of the thermoplastic composite 100 and a second member 32 at a secondside 102 of the thermoplastic composite 100. The method includesinductively heating a first heating element 48 that is positionedagainst the first member 31 and a second heating element 49 that ispositioned against the second member 32 (block 202). Heat is transferredfrom the first heating element 48 to the first member 31 and from thesecond heating element 49 to the second member 32 (block 204). Thethermoplastic composite 100 is heated through the first and secondmembers 31, 32 to the reconsolidation temperature (block 206). Heatingthe thermoplastic composite to this temperature reconsolidates thedelaminated section (block 208).

One example of a reconsolidation profile for carbon-reinforced PEKKthermoplastic APC (PEKK-FC)/AS4D 12K 145/34:

-   -   a. Attach the assembly and apply between about 100-500 psi to        the thermoplastic composite;    -   b. Heat at any rate to between about 710° F.-800° F.;    -   c. Maintain the pressure and heat for between about 15        minutes-30 minutes;    -   d. Cool down at a rate of about less than or equal to 100°        F./minute; In one example, Alloy 48 (48% nickel to iron) has a        Curie point range of between about 700° F.-775° F.

In one example as illustrated in FIG. 2, the assembly 10 includes twosusceptors 41, 42. Susceptor 41 is positioned at the first side 101 ofthe thermoplastic composite 100, and susceptor 42 is positioned at thesecond side 102 of the thermoplastic composite 100. The two susceptors41, 42 can be constructed from the same or different susceptor alloys.Further, the susceptors 41, 42 can include the same or different Curietemperatures. In another example, the assembly 10 includes a singlesusceptor. This includes either susceptor 41 at the first side 101, orsusceptor 42 at the second side 102.

In one example, the rod 21 is not a smart susceptor. The rod 21 can beconstructed from various materials, including but not limited to variousnon-ferrous materials. In another example, rod 21 is constructed from asusceptor alloy and includes a Curie temperature. During the heatingprocess, one or both of the induction coils 110, 111 cause the rod 21 toheat to its Curie temperature. The rod 21 thus causes heating and repairof the delaminated thermoplastic composite 100.

The thermoplastic composite 100 can be repaired while be used in a widevariety of contexts. One context includes the thermoplastic composite100 forming a structure on a vehicle. One example of a vehicle is acommercial aircraft used for transporting passengers and/or cargo. Oneexample of a vehicle structure is a wing or wing component of anaircraft. Other vehicles include but are not limited to unmannedaircraft, manned spacecraft, unmanned spacecraft, manned rotorcraft,unmanned rotorcraft, satellites, rockets, missiles, manned terrestrialaircraft, unmanned terrestrial aircraft, manned surface water borneaircraft, unmanned surface water borne aircraft, manned sub-surfacewater borne aircraft, unmanned sub-surface water borne aircraft, andcombinations thereof.

In the examples described above, the assembly 10 is used toreconsolidate thermoplastic composites. The assembly 10 can also be usedto heat thermoset materials. In one example, the assembly 10 is usedwith a small scarf configuration surrounding a hole in the thermosetmaterial. In another example, the assembly 10 is applied and used tocure potting compound that has been inserted to fill an oversized hole.During use with a thermoset material, the susceptors 41, 42 can be madefrom a material with a lower curie temperature than those used forthermoplastic materials.

The present invention may be carried out in other ways than thosespecifically set forth herein without departing from essentialcharacteristics of the invention. The present embodiments are to beconsidered in all respects as illustrative and not restrictive, and allchanges coming within the meaning and equivalency range of the appendedclaims are intended to be embraced therein.

What is claimed is:
 1. An assembly to repair a thermoplastic composite,the assembly comprising: a heating device comprising first and secondheating elements positioned on opposing sides of the thermoplasticcomposite, the first heating element comprising a first susceptor incontact with a first conductor and the second heating element comprisinga second susceptor in contact with a second conductor, the first andsecond susceptors each comprising a Curie temperature to heat andreconsolidate the thermoplastic composite; a pressure device to apply acompressive force to the heating device; and a pressure distributiondevice positioned between the heating device and the thermoplasticcomposite, the pressure distribution device having a greater widthmeasured along the thermoplastic composite than the heating device todistribute the compressive force from the pressure device over areas ofthe opposing sides of thermoplastic composite.
 2. The assembly of claim1, wherein the pressure distribution device comprises a first memberpositioned between the first heating element and a first side of thethermoplastic composite and a second member positioned between thesecond susceptor and a second side of the thermoplastic composite, thewidth of each of the first and second members is greater than theheating device.
 3. The assembly of claim 2, wherein the first and secondmembers comprise a tapered outer edge.
 4. The assembly of claim 1,wherein the pressure distribution device directly contacts against theheating device on each side of the thermoplastic composite.
 5. Theassembly of claim 1, wherein the pressure device comprises a rod sizedto extend through the thermoplastic composite with the first heatingelement and the first susceptor attached to the rod on a first side ofthe thermoplastic composite and the second heating element and thesecond susceptor attached to the rod on a second side of thethermoplastic composite.
 6. The assembly of claim 5, wherein the rod isconstructed from a susceptor alloy and has a Curie temperature to heatthe thermoplastic composite when the rod is heated by the heatingdevice.
 7. The assembly of claim 6, wherein the Curie temperature of thefirst susceptor is different than the second susceptor.
 8. The assemblyof claim 5, further comprising washer stacks positioned along the rodthat apply a force to the first and second heating elements to maintainthe compressive force.
 9. An assembly to repair a thermoplasticcomposite, the assembly comprising: a threaded rod; a nut threaded tothe threaded rod on a first side of the thermoplastic composite and anattachment on the threaded rod on a second side of the thermoplasticcomposite; first and second members positioned on the threaded rod withthe first member positioned between the nut and the first side of thethermoplastic composite and the second member positioned between theattachment and the second side of the thermoplastic composite; and firstand second heating elements positioned on the threaded rod with thefirst heating element positioned between the nut and the first memberand the second heating element positioned between the attachment and thesecond member, the first heating element comprising a first susceptorand a first conductor and the second heating element comprising a secondsusceptor and a second conductor, the first and second susceptors eachcomprising a Curie temperature to heat and reconsolidate thethermoplastic composite.
 10. The assembly of claim 9, wherein the firstand second members comprise an inner side that contacts against thethermoplastic composite and an outer side that contacts the first andsecond heating elements respectively.
 11. The assembly of claim 10,wherein the first and second members comprise a width W that is greaterthan the first and second heating elements.
 12. The assembly of claim 9,wherein the first susceptor contacts against the first conductor and thesecond susceptor contacts against the second conductor.
 13. The assemblyof claim 9, wherein the nut is a first nut, and the attachment is asecond nut that is threaded to the threaded rod.
 14. The assembly ofclaim 9, wherein the first heating element directly contacts against thefirst member and the second heating element directly contacts againstthe second member.
 15. The assembly of claim 9, wherein the threaded rodis constructed from a susceptor alloy that heats and reconsolidates thethermoplastic composite when heated by one or both the first and secondheating elements.
 16. A method of repairing a thermoplastic composite,the method comprising: compressing a delaminated section of thethermoplastic composite between a first member at a first side of thethermoplastic composite and a second member at a second side of thethermoplastic composite; inductively heating a first heating elementthat is positioned against the first member and a second heating elementthat is positioned against the second member, each of the first andsecond heating elements comprising a susceptor and a conductor in astacked configuration and with each of the susceptors comprising aCurrie temperature; transferring heat from the first heating element tothe first member and from the second heating element to the secondmember; and heating the thermoplastic composite through the first andsecond members and reconsolidating the delaminated section.
 17. Themethod of claim 16, further comprising: positioning a threaded rodthrough an opening in the thermoplastic composite; applying a torque toa nut on the threaded rod; and applying a compressive force to the firstand second heating elements and the first and second members.
 18. Themethod of claim 17, further comprising inductively heating the threadedrod to a corresponding Currie temperature and heating the thermoplasticcomposite with the threaded rod.
 19. The method of claim 16, furthercomprising positioning the first and second members outward beyond thefirst and second heating elements respectively and creating a thermaltransition zone along sections of the first and second members thatextend outward beyond the first and second heating elements.
 20. Themethod of claim 16, further comprising positioning a first one of thesusceptors directly against the first member and a second one of thesusceptors directly against the second member.